Taith Ddaearegol 2 gyda T H Evans, Ty Rhos / Geological Tour 2 with T H Evans, Ty Rhos

DISGYBLION YN ASTUDIO STRATA.               [ O’r County Echo 3-12-1908]

Ddydd Gwener casglodd nifer o fechgyn hynaf Ysgol Genedlaethol y Bechgyn ar Y  Bigni, dan ofal y Prifathraw (Mr E.W Rees) i gyfarfod a Mr T H Evans, Yr oedd ef, yn garedig, wedi ymgymeryd i roddi iddynt hyfforddiant ymarferol ac ocwlar ar ffurfiant daearyddol eu sir genedigol, pwnc y maent i sefyll arholiad ynddo yn fuan.

Cynhyrchodd Mr Evans fap o Sir Benfro, ynghyd â chwmpawd, a nododd berthynas y gwahanol haenau i’r offeryn, gan nodi eu bod, yn y fan a’r lle, yn sefyll ar graig igniws, a bod llwybr y rheilffordd yn datgelu lludw felspathig yn rhanbarth ‘Pen-cw’. Dangosodd pa mor gul oedd y gwythiennau hyn yn Sir Benfro, a sut yr oeddent yn ymestyn fel arfer o’r Dwyrain i’r Gorllewin hefyd eu bod wedi’u hamgylchynu gan greigiau haenog, megis llechi. Amlygwyd y ffaith hon gan ymweliad â chwarel lechi Mr Vaughan yn Drim.

Ymwelwyd nesaf a’r traeth, lle, yn ffodus, gyda’r llanw allan, galluogwyd y myfyrwyr i sylwi fod y ffurfiant llechi yn ymestyn ar hyd ochr dde’r Parrog i gyd, ac yn cynnwys gwythïen gwarts, o’r bath a weithir ac a  gloddir am fwynau o werth masnachol. Cynyrchodd y darlithydd ddarn o gwarts cyfatebol, yr hwn a ddygasai efe ei hun o Alaska, ac yn yr hwn yr oedd aur yn weledig i’r llygad noeth. Eglurodd y dulliau a fyddai wedi’u mabwysiadu ar gyfer mwyngloddio pe bai’r cwarts yn Wdig o gymeriad ‘cynnwys aur’. Wedi hyn, trowyd i’r hen bwll tywod gerllaw Llwybr Pencowrw, lle nododd sut roedd y tywod yn cyfateb gyda’r hyn yr oedd y myfyrwyr wedi ei ganfod yn Cnwc sandy ar achlysur darlith flaenorol.

Aeth y fintai yn ei flaen oddiyno ar hyd y lan i Ben-slad, ac ymgynull ym mhen uchaf Llanpit Mawr, a  chyfeiriwyd eu sylw at y ffaith, wrth edrych tua Shaffre, fod cwymp diweddar o graig wedi datguddio ffurfiant naturiol yn debyg i risiau celfydd. Dangoswyd iddynt hefyd fod ffurfiant grisialaidd cyfatebol yn bodoli yn Llanpit Mawr. Tynnodd Mr Evans sylw at y modd yr oedd y crisialu hwn wedi arwain at erydiad yr arfordir, a dywedodd fod Cymru, yn ôl pob tebyg, unwaith wedi ymestyn dros holl Fae Ceredigion, a bod y chwedl am fodolaeth lle o’r enw Cantref-y- gwaelod, mae’n debyg, yn wir. Ar hyd y prynhawn dangosodd y myfyrwyr ddiddordeb deallus iawn yn y drafodaeth addysgiadol, a diolchwyd yn galonog i Mr Evans am ei wasanaeth caredig.

SCHOLARS STUDY STRATA.                                [ From The County Echo 3-12-1908]

On Friday a number of the senior scholars of the Boys’ National School assembled on Biggni, under the charge of the Headmaster (Mr E W Rees) to meet Mr T H Evans, who  had kindly undertaken to give them practical and ocular instruction in the geographical formation of their native county, a subject in which they are shortly to sit for examination.

Mr Evans produced a map of Pembrokeshire, together with a compass, and pointed out the relation of the various strata to the instrument, remarking that, at that spot, they were standing upon ignious rock, and  that the railway cuttings revealed felspathic ashes in the region of ‘The Cw‘. He showed how narrow these veins were in Pembrokeshire, and how they extended usually from East to West also that they were surrounded by stratified rocks, such as slate. This fact was exemplified by a visit to Mr Vaughan’s slate quarry at Drim.

A visit was next paid to the beach, where, the tide being fortunately out, the students were enabled to observe that the slate formation extended along the whole of the right-hand side of the Parrog, and contained a quartz vein, such as was worked for the extraction of minerals of commercial value. The lecturer produced a piece of corresponding quartz, which he had himself brought from Alaska, and in which gold was visible to the naked eye. He explained the methods which would have been adopted for mining had the quartz at Goodwick been of a ‘gold-bearing’ character, after which adjournment was made to the old sand pit adjacent to the French Walk, where he pointed out how the sand corresponded with that which the students had examined at Cnwc sandy upon the occasion  of a previous lecture.

The party proceeded thence along the shore to Penslade, and reassembled at the top of Llanpit Mawr, where their attention was directed to the fact that, looking towards Shaffre, a recent fall of rock had disclosed a natural formation resembling artificial steps. They were also shown that a corresponding crystalline formation existed at Llanpit Mawr. Mr Evans, pointed out how this crystallisation had resulted in coast erosion, and remarked that, in all probab- ility Wales had once extended over the whole of Cardigan Bay, and that the legend of the former existnce of a place called Cantref-y- gwaelod was probably true. Throughout the afternoon the students exhibited a most intelligent interest in the instructive discourse of which they were treated, and at the close Mr Evans was heartily thanked for his disinterested services.